Bally Alpha power supply failures

[slotdoofus]

I've learned through my years of pinball repair that most electronic component failures are caused by heat build-up. This can be caused by electrical current resistance, or, in this case, (I think) the cooling fans failing.

I now have a stack of 5/12 volt and 24 v Bally power supplies that no longer work. I went and looked at all of my working machines. BOTH of the cooling fans on the 5/12 v power supplies no longer work. I'm going to order a butt-load of these and replace every single cooling fan in all of my power supplies. These ADDA fans can be a bit costly. I plan on ordering some no-name brands from China at 1/10th the cost of the ADDAs.

[slotdoofus]

I have a stack of (4) 24 volt power supplies that are bad. I have (3) 5/12 volt power supplies that are bad.

Is there a common component that usually fails on these power supplies? Considering the power supplies have all thru-hole components, I don't think repairing them would be all that difficult. It sure looks a lot easier to repair than these pinball circuit boards I've been repairing for years.

[idesign]

Usually the electrolytic caps are the issue.  Looks for bulging caps.

[slotdoofus]

That was the 1st thing I looked at. I see several that are bulging...no signs of any leakage.

I'll probably check w/ GPE or Mouser and buy me some caps.

Thanks

[idesign]

If bulging they failed or are about to fair. They usually don't explode so chaneces are they won't mess up the board.